Improvement in sewing-machines



No. 31,423. PATENTED FEB. 12, 1861,

' 0. W. WILLIAMS.

SEWING MACHINE.

[zit safer UNITED STATES PATENT QFFICE.

G. WV. WILLIAMS, OF BOSTOhl, MASSACHUSETTS.

IMPROVEMENT IN SEWING-MACHINES.

Specification forming part of Letters Patent No. 31,423, dated February 12, 18(31.

To all whom it mag concern:

Be it known that'I, 0. W. WILLIAMs, of Boston, in the county of Sufi'olk and State of Massachusetts, have invented a new and useful Improvement in Sewing-Machines; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming part of this specification.

My invention relates to the use of a clampin g device attached to the bar or carrier of the perforating-needle for the purpose of clam ping the thread of the said needle firmly against thesaid bar or carrier during the first part of the ascent or withdrawing movement of the said needle, and so causing the thread to be drawn up through the cloth with the needle and preventing any loop from being thrown out on the wrong side of the needle and preventing the thread from being drawn back through the eye of the said needleand there by insuring a proper quantity of slack being thrown out from the said needle on the proper side for the entry of the looping device. By the means heretofore-used for operating such a clamping device it is made to clamp the thread at one stage of the downward or perforating movement of the needle, which is very objectionable; and my invention consists in certain improved means of operating the said clamping device, whereby itis caused to clam p the thread at a certain stage of the stitch-mak in g operation, as hereinafter eXplained,-but is prevented clamping the thread dnrin g the perrotating movement ofthe needle and during any greater portion of the withdrawing movement than is necessary.

To enable others skilled in the art to make and use my invention, I will proceed to de scribe it with reference'to the accompanying drawings, in which-- Figure 1 is a side view of the needle-bar, the clamping device, and the parts of the machine thereto adjacent. Fig. 2 is a front view of the same. Fig. 3 is a perspective viewofthe clamping device and itsimmediate appendages. Fig. 4 is a perspective view of the principal details of the said device.

Similar letters of reference indicate corresponding parts in the several figures.

A is part of the stationary arm of the machine carrying or containing the guides for the needle-bar B.

(J O are two pressers. V

l) is a spring attached to the arm A for taking up the slack of the needle-thread as the said thread is drawn up through the cloth.

a is a stationary thread-guide" on the top of the bar'by the pin 11 passing loosely throngli holes 0 ein the said lugs, the said pin thus serving as a pivot, upon which thejaw G has the slight amountofswinging movement which is necessary for the clamping and unclamping of the thread passing between it and the jaw 1*. This swinging movement is controlled by a set-screw, f, passing through a hole, g, in the jaw and screwing into the needle-bar. The jaw Gis also furnished. with a tongue, h, which stands out from the needle-bar, and which has an outward bevel, 5, from its lower edge and an inward bevel, 6, from its upper edge.

H is an elastic, but not too flexible, switch, secured to the arm A, and having the piece t at its upper end made with an outward bevel, 7, from its lower edge, and an inward bevel, 8, from its upper edge. This switch is so arranged that almost as soon as theneedle-bar commences rising the upper bevel, 6, of the tongue h of the jaw G comes in contact with the lower bevel, 7, of the switch, and as the needle-bar continues rising the said tongue is caused to pass outside of the switch, as shown in Fig. 1; but that as the needle-bar descends the lower bevel, 5, of the said tongue h strikes the upper bevel, 8, of the switch, as shown in Fig. 3, and the said tongue is so caused to pass inside of the switch. the above-mentioned operation of the tongue h and switch is as follows: The thread represented in red color in Figs. 1 and 2 comes from a suitably-arranged spool through any suitable tension device, through an eye at the extremity of the take-up spring D, through i the fixed guidea, and from thence between the The effect produced by,

i to be clamped between the said jaws.

' clamping operation, which only continues durjaws F G of the clamping device to the eye ofthe =perforating-needle n; No pressure is produced upon'the' thread when the tongue h is-out of contact with the switch, as. the jaw G then hangs perfectly loose; but in the upward movement of the needle-bar to withdraw the needle from the cloth the pressure of the switch against the inside of the tongue h, as the latter passes it, is madeto force the jaw G toward the jaw F, and so to cause the-thread This ing the first part of the upward movement of the needle, prevents the friction of the cloth producing a slackness of the thread on the opposite side to that on which the under needle, I, or other looping device works, and also prevents the take-up spring from drawing ,the thread back through the eye of the needle and so insures the throwing out of the loop on the proper side of the needle and at the proper time for the looping device tof'enter it. It is not to this operation, however, that my invention so particularly relates, as to the prevention of a similar clamping [operation taking place as the needle descends. This prevention is effected by the tongue h passing inside I jaw G as far away from F as the set-screw permits, and so causes the thread to be left free ated.

I do not claim to be. the first inventor of a clamp to hold the thread during a part of the motion of t-heneedle; neither do I claim to be thefirst to operate such a clamp by means of an oppositely-beveled spring-switch but What I claim as new and of my invention,

and desire to secure by Letters Patent, is-

The peculiar combination of thejaws F and G, donbly-beveled'tongue h, and doubly-beveled switch H t, the said parts being constructed and arranged as'herein shown and described,

and operating in the manner explained, to cause the clamping of the thread duringihe early stage of the withdrawing of the-needle and prevent the clam ping thereof durin g the downward stroke. I

o. W. W1LLrAMs. Witnesses:

L. P.- PEASE, T. G. BURKE. 

